Dublin Institute for Advanced Studies

Gravity Data

DIAS Geophysics has collected and continues to manage terrestrial gravity data In Ireland.

Since the establishment of the Geophysics Section, gravity measurements were taken at over 23,000 stations (Thirlaway 1951, Murphy 1952, 1974; , O’Reilly et al., 1996, Readman et al., 1997). The data coverage shown averages at about 4.2 stations per 10 km square, equivalent to an average spacing of about 1.55 km. The measurements have usually been made at or near to Ordnance Survey of Ireland bench marks or spot heights, and terrain corrections (rarely greater than 0.5 mGal) have been made where necessary. To view gravity station locations click here.

The overall accuracy is estimated to be about 0.2 mGal. The variation in the thickness of the overburden cover leads to uncertainty in calculating the Bouguer anomaly that in extreme cases can be up to 1.5 mGal for peat bog. The magnitude of the effect is rarely known so for simplicity the data reduction procedure in calculating the Bouguer anomaly has assumed a constant density of 2670 kg m -3 above sea-level datum.

Commercial data licence fee

€0.30 per point (for one year licence) + €250 licensing fee and €250 data preparation fee.

Multi-year licences are possible up to a maximum of 5-years, with approximately 50% reduction for each successive year so a 2 year licence is €0.45 per point, 3 year licence is €0.525 per point, 4 year licence is €0.5625 per point, and a 5 year licence is €0.60 per point.

The field season of the DIAS led HERSK project started last week when Icelandic Met Office engineers transported seismic gear with skidoos onto Hekla volcano. The HEkla Real-time Seimic networK project
is funded by the GSI shortcall program and led by Martin Möllhoff at DIAS.

This inflation has critically stressed the rocks in the volcano, such that small local earthquakes are being triggered by the tiny ground shaking from large distant earthquakes in the surrounding Pacific ‘ring of fire’.

Geophysicists from DIAS have recently assisted the University of Edinburgh & the Instituto Geofisico at the Escuela Politecnica Nacional (IGEPN), deploy a network of seismometers at Sierra Negra, a large basaltic volcano in the Galapagos Islands, Ecuador.

#DIASDublin welcomed Mr. Yukiya Amano, DG of the International Atomic Energy Agency @iaeaorg today where, as a guest of the Department of Foreign Affairs and Trade, he gave a keynote address on "IAEA: Atoms for Peace and Development". Retweeted by
DIAS Geophysics